This model is part of the tetramagic series. It combines the first and the last solution of the "K4 not edge magic but..." problem. The two parts are interlocked and cannot be separated. Please refer to a related model
https://www.shapeways.com/product/59ZHKY8WD/tetramagic19 for more details.
By the way, beause the parts move and touch each other, even the bronze model makes a silver sound like a bell when worn as a pendant.